## General Science Forces and Energy Flash Card Set 225670

 Cards 10 Focus Forces and Energy Topics Force, Kinetic Energy, Magnetism, Mass vs. Weight, Power, Weight, Work

#### Study Guide

###### Force

Force is applied to change an object's speed or direction of motion.

###### Kinetic Energy

Kinetic energy is the energy posessed by a moving object. Potential energy is stored energy in a stationary object based on its location, position, shape, or state.

###### Magnetism

Simple magnets have two poles, north and south, and opposite poles attract each other (N attracts S, S attracts N). Likewise, the same pole of two magnets repel (N repels N, S repels S). The Earth has a magnetic field and North and South Poles which enables the use of a magnetic compass to determine direction.

###### Mass vs. Weight

Mass is the amount of matter something has while weight is the force exerted on an object's mass by gravity. So, although a person's mass doesn't change when going from the Earth to the Moon, their weight will decrease because the force of the Moon's gravity is much less than that of Earth.

###### Power

Power is the rate at which work is performed or work per unit time: $$P = {w \over t}$$ and is measured in watts (W).

###### Weight

Weight is a force that describes the attraction of gravity on an object. Force is measured in newtons (N) with 1 N being the force required to impart an acceleration of 1 m/s2 to a mass of 1 kg.

###### Work

Work is performed on an object when an applied force causes displacement along the same vector. Measured in joules (J) or newton-meters (Nm), work is calculated by multiplying force times displacement: $$W = \vec{F}\vec{d}$$